I agree with you on that. I did find this on a search....
"(TechnicalUser) 16 Mar 12 9:47
From my own experience, these phones have standard SIP support only when you have it connected to a VCX server. The phones have no way of retaining firmware settings like your typical endpoints, so, once you power the phone off it kind of forgets where it is. After some enterprising tweaking at my company with the B model phones we got them to register, albeit lamely in Asterisk . I say lamely because you couldn't adjust button mapping.
So for the TL;DR answer: no, no such luck in my case (yet)"
Its not worth the labor to fight these phones.